RESUMEN
Biomaterials derived from biological matrices have been widely investigated due to their great therapeutic potential in regenerative medicine, since they are able to induce cell proliferation, tissue remodeling, and angiogenesis in situ. In this context, highly vascularized and proliferative tissues, such as the uterine wall, present an interesting source to produce acellular matrices that can be used as bioactive materials to induce tissue regeneration. Therefore, this study aimed to establish an optimized protocol to generate decellularized uterine scaffolds (dUT), characterizing their structural, compositional, and biomechanical properties. In addition, in vitro performance and in vivo biocompatibility were also evaluated to verify their potential applications for tissue repair. Results showed that the protocol was efficient to promote cell removal, and dUT general structure and extracellular matrix composition remained preserved compared with native tissue. In addition, the scaffolds were cytocompatible, allowing cell growth and survival. In terms of biocompatibility, the matrices did not induce any signs of immune rejection in vivo in a model of subcutaneous implantation in immunocompetent rats, demonstrating an indication of tissue integration after 30 days of implantation. In summary, these findings suggest that dUT scaffolds could be explored as a biomaterial for regenerative purposes, which is beyond the studies in the reproductive field.
RESUMEN
The aim of this study was to compare the clinical, tomographic, and histological performance of collagenated xenogeneic bone blocks (CXBB) in horizontal bone augmentations for implant placement. Five patients with an absence of the 4 upper incisors and an HAC 3 horizontal bone defect, with a remaining of 3 to 5 mm, underwent a bone-grafting procedure with CXBB (test group [TG], n = 5) and autogenous graft (control group [CG], n = 5), with one type of graft used on the right side and other type on the left side. Changes in bone thickness and density (tomographic evaluation), levels of complications (clinically), and distribution pattern between mineralized and nonmineralized tissue (histomorphometrically) were analyzed. Tomographic analysis showed a horizontal bone increase of 4.25 ± 0.78 mm in the TG and 3.08 ± 0.8 mm in the CG between baseline and 8 months postoperatively (P < .05). The horizontal loss between the day of installation of the blocks and 8 months postoperatively was 1.02 ± 0.39 mm for the TG and 1.10 ± 0.71 mm for the CG (P > .05). With regard to bone density, the TG blocks right after installation had 440.2 ± 89.15 HU, and after 8 months, the region reached 730.7 ± 130.98 HU, representing an increase of 29.05%. For the CG blocks, bone density increased from 1052.2 ± 398.35 HU to 1222.5 ± 453.28 HU, representing an increase of 17.03%. The increase in bone density was significantly higher in the TG (P < .05). Clinically, no cases of exposure of the bone blocks and no failure of incorporation were observed. Histomorphometrically, the percentage of mineralized tissue was lower in the TG than in the CG (48.10% ± 2.88% and 53.53% ± 1.05%, respectively), and the opposite was verified for the levels of nonmineralized tissue (52.79% ± 2.88% and 46.47% ± 1.05%, respectively; P < .05). The use of CXBB achieved higher levels of horizontal gain, with lower bone density and lower levels of mineralized tissue when compared with the use of autogenous blocks.
Asunto(s)
Aumento de la Cresta Alveolar , Implantación Dental Endoósea , Humanos , Implantación Dental Endoósea/métodos , Proyectos Piloto , Estudios Prospectivos , Aumento de la Cresta Alveolar/métodos , Boca , Trasplante Óseo/métodosRESUMEN
This case report describes the successful 10-years interdisciplinary treatment of ankylosed upper central incisors with an anterior vertical ridge defect. This treatment was challenging as ankylosis was present before the growth spurt. Orthodontic treatment in association with decoronation, a xenogeneic bone graft, an autogenous sub-epithelial connective tissue graft, and implant placement were performed to correct the vertical ridge defect and to re-establish appropriate function, gingival health, and aesthetics. Decoronation performed during the growth spurt was the key to avoiding alveolar ridge deformity.
Asunto(s)
Aumento de la Cresta Alveolar , Anquilosis del Diente , Avulsión de Diente , Humanos , Proceso Alveolar , Incisivo/cirugía , Anquilosis del Diente/cirugía , Avulsión de Diente/terapia , Corona del Diente , Masculino , NiñoRESUMEN
The aim of this study was to evaluate neovascularization of bovine xenografts implanted in intracorporeal sites of rabbits (bioreactors). 30 rabbits were used, divided into 6 groups, according to the evaluation time (7, 15, 30, 45, and 60 days); each animal received xenogenic implants in 3 different intracorporeal sites (A1 - omentum bag; A2 - intermuscular space of quadriceps femoris; A3 - subperiosteal of ilium bone). Histological assessments graded the presence of angiogenesis, the number of inflammatory cells, newly formed bone tissue, and the presence of giant cells. Histological analyses showed intense angiogenesis in all implanted xenografts. Presence of inflammatory infiltrate and giant cells at the A1 implant site and presence of bone neoformation at the A3 implant site were noted. Degeneration of implants and formation of a fibrous capsule were noted. When comparing the interaction of the site with the days of evaluation, statistical analysis showed a significant difference (p≤0.05) in any time of neovascularization analysis. The vascular endothelial growth factor (VEGF) and inflammatory cells of the omentum in its structure, may have contributed to the greater presence of neovessels and inflammatory cells, a fact that may indicate functionality as a possible bone substitute.(AU)
O objetivo deste estudo foi avaliar a neovascularização de xenoenxertos bovinos implantados em sítios intracorpóreos de coelhos (biorreatores). Foram utilizados 30 coelhos, os quais foram divididos em seis grupos, de acordo com o tempo de avaliação (sete, 15, 30, 45 e 60 dias); cada animal recebeu implantes xenogênicos em três diferentes sítios intracorpóreos (A1 - bolsa de omento; A2 - espaço intermuscular do quadríceps femoral; A3 - subperiosteal do osso ílio). Avaliações histológicas classificaram a presença de angiogênese, o número de células inflamatórias, de tecido ósseo neoformado e a presença de células gigantes. As análises histológicas mostraram intensa angiogênese em todos os xenoenxertos implantados. Observou-se presença de infiltrado inflamatório e células gigantes no local do implante A1 e presença de neoformação óssea no local do implante A3. Ao mesmo tempo, a degeneração dos implantes e a formação de uma cápsula fibrosa foram observadas. Ao comparar a interação do local com os dias de avaliação, a análise estatística mostrou diferença significativa (P≤0,05) em qualquer momento da análise de neovascularização. O fator de crescimento endotelial vascular (VEGF) e as células inflamatórias do omento em sua estrutura podem ter contribuído para a maior presença de neovasos e células inflamatórias, fato que pode indicar funcionalidade como possível substituto ósseo.(AU)
Asunto(s)
Animales , Bovinos , Conejos , Trasplante Óseo/veterinaria , Reactores Biológicos/veterinaria , Xenoinjertos/irrigación sanguínea , Modelos AnimalesRESUMEN
OBJECTIVES: This study aimed to compare xenogeneic dermal matrix (XDM) to connective tissue graft (CTG) associated with coronally advanced flap (CAF) in treating Miller's class I and II (RT1) multiple gingival recession in a split-mouth randomized clinical trial. MATERIALS AND METHODS: Fifteen patients with bilateral Miller's class I and II multiple recessions were selected. The patient's side receiving each treatment was randomly allocated to receive XDM or CTG. The clinical parameters were measured at baseline and 6 months of follow-up. RESULTS: At 6 months, no significant difference in the root coverage (RC) (95.28 ± 6.89% for CTG and 92.68 ± 7.35% for XDM) and the keratinized tissue (KT) gain (0.91 ± 0.46 mm for CTG and 0.74 ± 0.39 mm for XDM) was observed between groups (p > 0.05). The CTG group presented higher complete root coverage (CRC) than XDM (60% and 33%, respectively) (p = 0.045). Multiple logistic regression indicated that the XDM (p = 0.01) and the XDM and KT interaction (p = 0.02) negatively interfered in the CRC. A 1-mm increase in the baseline KT when using XDM increases almost 6 times the chance of achieving CRC, and XDM reached a similar CRC probability to CTG when the receptor area presented at least 2 mm of KT. CONCLUSIONS: Both treatments were effective for treating multiple gingival recession; similar KT gain, GR reduction, and RC were obtained for CTG and XDM, while CTG promoted higher CRC than XDM. Moreover, the amount of KT at baseline was determinant for CRC when treating multiple gingival recession with XDM. CLINICAL RELEVANCE: XDM produces limited CRC in sites with a reduced amount of KT. TRIAL REGISTRATION: Brazilian Clinical Trials Registry (REBEC) number RBR-56NZQ6.
Asunto(s)
Dermis Acelular , Recesión Gingival , Tejido Conectivo , Encía , Recesión Gingival/cirugía , Humanos , Raíz del Diente/cirugía , Resultado del TratamientoRESUMEN
Acquisition of mobile elements by horizontal gene transfer can play a major role in bacterial adaptation and genome evolution by providing traits that contribute to bacterial fitness. However, gaining foreign DNA can also impose significant fitness costs to the host bacteria and can even produce detrimental effects. The efficiency of horizontal acquisition of DNA is thought to be improved by the activity of xenogeneic silencers. These molecules are a functionally related group of proteins that possess affinity for the acquired DNA. Binding of xenogeneic silencers suppresses the otherwise uncontrolled expression of genes from the newly acquired nucleic acid, facilitating their integration to the bacterial regulatory networks. Even when the genes encoding for xenogeneic silencers are part of the core genome, homologs encoded by horizontally acquired elements have also been identified and studied. In this article, we discuss the current knowledge about horizontally acquired xenogeneic silencer homologs, focusing on those encoded by genomic islands, highlighting their distribution and the major traits that allow these proteins to become part of the host regulatory networks.
Asunto(s)
Bacterias/genética , Proteínas Bacterianas/genética , Bacteriófagos/genética , Plásmidos/genética , Bacterias/virología , Regulación Bacteriana de la Expresión Génica , Transferencia de Gen Horizontal , Aptitud Genética , Islas GenómicasRESUMEN
Mobile Genetic Elements (MGEs) are mosaics of functional gene modules of diverse evolutionary origin and are generally divergent from the hosts´ genetic background. Existing biases in base composition and codon usage of these elements` genes impose transcription and translation limitations that may affect the physical and regulatory integration of MGEs in new hosts. Stable appropriation of the foreign DNA depends on a number of host factors among which are the Nucleoid-Associated Proteins (NAPs). These small, basic, highly abundant proteins bind and bend DNA, altering its topology and folding, thereby affecting all known essential DNA metabolism related processes. Both chromosomally- (endogenous) and MGE- (foreign) encoded NAPs have been shown to exist in bacteria. While the role of host-encoded NAPs in xenogeneic silencing of both episomal (plasmids) and integrative MGEs (pathogenicity islands and prophages) is well acknowledged, less is known about the role of MGE-encoded NAPs in the foreign elements biology or their influence on the host's chromosome expression dynamics. Here we review existing literature on the topic, present examples on the positive and negative effects that endogenous and foreign NAPs exert on global transcriptional gene expression, MGE integrative and excisive recombination dynamics, persistence and transfer to suitable hosts and discuss the nature and relevance of synergistic and antagonizing higher order interactions between diverse types of NAPs.
RESUMEN
Xenotransplantation could provide an unlimited supply of organs and solve the current shortage of organs for transplantation. To become a reality in clinical practice, the immunological and physiological barriers and the risk of xenozoonosis that they possess should be resolved. From the immunological point of view, in the last 30 years a significant progress in the production of transgenic pigs has prevented the hyperacute rejection. About xenozoonosis, attention has been focused on the risk of transmission of porcine endogenous retroviruses; however, today, it is considered that the risk is very low and the inevitable transmission should not prevent the clinical xenotransplantation. Regarding the physiological barriers, encouraging results have been obtained and it's expected that the barriers that still need to be corrected can be solved in the future through genetic modifications.
Asunto(s)
Trasplante Heterólogo , Animales , Humanos , Infecciones/epidemiología , Complicaciones Posoperatorias/epidemiología , Factores de Riesgo , Inmunología del TrasplanteRESUMEN
Mesenchymal stem/stromal cells (MSC) are being widely explored as promising candidates for cell-based therapies. Among the different human MSC origins exploited, umbilical cord represents an attractive and readily available source of MSC that involves a non-invasive collection procedure. In order to achieve relevant cell numbers of human MSC for clinical applications, it is crucial to develop scalable culture systems that allow bioprocess control and monitoring, combined with the use of serum/xenogeneic (xeno)-free culture media. In the present study, we firstly established a spinner flask culture system combining gelatin-based Cultispher(®) S microcarriers and xeno-free culture medium for the expansion of umbilical cord matrix (UCM)-derived MSC. This system enabled the production of 2.4 (±1.1) x10(5) cells/mL (n = 4) after 5 days of culture, corresponding to a 5.3 (±1.6)-fold increase in cell number. The established protocol was then implemented in a stirred-tank bioreactor (800 mL working volume) (n = 3) yielding 115 million cells after 4 days. Upon expansion under stirred conditions, cells retained their differentiation ability and immunomodulatory potential. The development of a scalable microcarrier-based stirred culture system, using xeno-free culture medium that suits the intrinsic features of UCM-derived MSC represents an important step towards a GMP compliant large-scale production platform for these promising cell therapy candidates.
Asunto(s)
Técnicas de Cultivo Celular por Lotes/métodos , Células Madre Mesenquimatosas/citología , Cordón Umbilical/citología , Reactores Biológicos , Recuento de Células , Diferenciación Celular , Proliferación Celular , Humanos , Inmunofenotipificación , Células Madre Mesenquimatosas/inmunología , Cordón Umbilical/inmunologíaRESUMEN
Fish germ cell transplantation presents several important potential applications for aquaculture, including the preservation of germplasm from endangered fish species with high genetic and commercial values. Using this technique in studies developed in our laboratory with adult male Nile tilapias (Oreochromis niloticus), all the necessary procedures were successfully established, allowing the production of functional sperm and healthy progeny approximately 2months after allogeneic transplantation. In the present study, we evaluated the viability of the adult Nile tilapia testis to generate sperm after xenogeneic transplant of germ cells from sexually mature Jundia catfish (Rhamdia quelen) that belong to a different taxonomic order. Therefore, in order to investigate at different time-periods post-transplantation, the presence and development of donor PKH26 labeled catfish germ cells were followed in the tilapia seminiferous tubules. From 7 to 20days post-transplantation, only PKH26 labeled spermatogonia were observed, whereas spermatocytes at different stages of development were found at 70days. Germ cell transplantation success and progression of spermatogenesis were indicated by the presence of labeled PKH26 spermatids and sperm on days 90 and 120 post-transplantation, respectively. Confirming the presence of the catfish genetic material in the tilapia testis, all recipient tilapias evaluated (n=8) showed the genetic markers evaluated. Therefore, we demonstrated for the first time that the adult Nile tilapia testis offers the functional conditions for development of spermatogenesis with sperm production from a fish species belonging to a different order, which provides an important new venue for aquaculture advancement.
Asunto(s)
Bagres/metabolismo , Trasplante de Células , Xenoinjertos/citología , Espermatozoides/citología , Testículo/citología , Tilapia/metabolismo , Trasplante Heterólogo , Animales , Acuicultura/métodos , Bagres/genética , Conservación de los Recursos Naturales/métodos , Especies en Peligro de Extinción , Xenoinjertos/crecimiento & desarrollo , Masculino , Túbulos Seminíferos/citología , Espermátides/citología , Espermátides/crecimiento & desarrollo , Espermátides/metabolismo , Espermatocitos/citología , Espermatocitos/crecimiento & desarrollo , Espermatocitos/metabolismo , Espermatogénesis , Espermatogonias/citología , Espermatogonias/crecimiento & desarrollo , Espermatogonias/metabolismo , Espermatozoides/crecimiento & desarrollo , Espermatozoides/metabolismo , Testículo/fisiología , Tilapia/genéticaRESUMEN
Um dos recursos recentes da engenharia tecidual para auxiliar no tratamento de defeitos ósseos é a proteína morfogenética óssea recombinante BMP-2 (rhBMP-2) que, entre outros fatores, permite melhorar a previsibilidade de volume e contorno de um procedimento de enxertia óssea. Para que seus resultados sejam satisfatórios, é necessário conhecer suas características, vantagens e limitações. O presente trabalho apresentou um caso clínico de grande demanda estética, no qual foi utilizada combinação de rhBMP-2 com osso desproteinizado e tela de titânico para garantir um contorno ósseo adequado na região da maxila anterior. As indicações, características, vantagens e desvantagens do rhBMP-2 como auxiliar em tratamentos de regeneração óssea também foram apresentadas e discutidas...
A recent resource for tissue engineering to assist in the treatment of bone defects is recombinant human bone morphogenetic protein BMP-2 (rhBMP-2), which, among other effects, improves the predictability of the volume and contour of bone grafting procedures. For a satisfactory outcome, it is important to know its characteristics, advantages and limitations. This paper presents a case of great aesthetic demand where the rhBMP-2 was used in combination with deproteinized bone and titanium mesh to ensure adequate bone contour in the anterior maxillary region. The indications, characteristics, advantages and disadvantages of rhBMP-2 as an aid in bone regeneration treatments are also presented and discussed...
Asunto(s)
Humanos , Femenino , Anciano , Regeneración Ósea , Trasplante Óseo , Implantes Dentales , Maxilar , Estética DentalRESUMEN
O objetivo desse artigo foi demonstrar metodologias de preservação da arquitetura gengival em região estética por meio de diferentes tipos de compensações, nas situações de alvéolo cicatrizado, alvéolo fresco íntegro e alvéolo fresco comprometido. As opções de compensações utilizadas em cada caso se mostraram eficientes, de fácil reprodutibilidade e permitiram a manutenção e preservação das características gengivais.
The aim of this article was to demonstrate methods to preserve the gingival architecture in three different alveolar socket situations: healed, fresh intact, and fresh compromised. All options were effective, easy to reproduce, and allow for maintenance of gingival characteristics.
Asunto(s)
Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Estética Dental , Carga Inmediata del Implante Dental , Rehabilitación Bucal , Alveolo Dental , TrasplantesRESUMEN
Apesar do avanço no conhecimento científico biológico e com melhores instrumentos para o planejamento, a perda de dois elementos dentários contíguos na região maxilar anterior continua sendo um grande desafio estético quando utilizamos a terapia com implantes osseointegrados. Este artigo apresenta um caso clínico no qual uma paciente de 25 anos teve dois incisivos centrais perdidos, por reabsorção interna e externa após trauma e tratamento endodôntico, substituídos por implantes dentários. Enquanto no sítio do elemento 21 foi possível instalar um implante imediatamente após a extração, com provisório imediato, no sítio do elemento 11 foi necessária a execução de regeneração tecidual guiada. Um bloco de material xenógeno bovino desproteinizado (Bio-Oss Block) foi utilizado em conjunto com uma membrana de colágeno natural suíno (Bio-Gide) para este fim. Após seis meses, um implante foi instalado no sítio 21. Após a moldagem e escaneamento, dois pilares de zircônia e duas coroas de cerâmica com base de zircônia foram fabricados, instalados e cimentados de maneira precoce, 12 dias após a segunda implantação. O controle após seis meses demonstra boa estabilidade dos tecidos.
Although advances on treatment planning tools and biological knowledge have been made, the loss of two adjacent teeth in the anterior maxilla continues to be a great esthetic challenge when dental implants are to be inserted. This case report presents a 25 years-old patient where the two central incisors had to be removed due to internal and external root resorption after trauma and endodontic therapy. While in the region of tooth 21 it was possible to insert a dental implant soon after tooth removal, a guided tissue regeneration procedure was necessary at the region of 11. Thus, a deproteinized bovine xenogeneic bone block (Bio-Oss Block) was grafted along with a natural collagen porcine membrane (BioGide). After six months, a dental implant was placed in the same region. After impression and scanning, two zirconia abutments and zirconia-based defi nitive ceramic crowns were fabricated and cemented 12 days after the second implant surgery. The six-moth postoperative results demonstrate good tissue stability.
Asunto(s)
Humanos , Femenino , Adulto , Estética Dental , Carga Inmediata del Implante Dental , OseointegraciónRESUMEN
Este trabalho teve como objetivo avaliar a propriedade biológica e a biocompatibilidade do osso composto e do osso integral de origem bovina, implantados em cavidades ósseas de tíbias e no plano subcutâneo de ratos. Foram utilizados 24 ratos sacrificados após 15 e 45 dias. Os resultados do exame microscópico das peças obtidas do subcutâneo mostraram aos 15 dias uma reação inflamatória ao redor das partículas do material com presença de células gigantes e, aos 45 dias, observou-se diminuição da reação inflamatória e presença de tecido conjuntivo fibroso ao redor das partículas com a presença de células gigantes. Não houve indícios de formação óssea ectópica nas peças histológicas obtidas da tíbia; foi possível observar maior atividade de neoformação óssea no grupo controle aos 15 dias com 42,8% da cortical externa sendo neoformada em comparação aos 22,6% do grupo Orthogen e 25% do grupo GenMix. Aos 45 dias havia 62,5% de neoformação óssea no grupo controle, 26% no grupo Orthogen e 35% no grupo GenMix. Pôde-se concluir que o osso composto e o osso integral de origem bovina são materiais biocompatíveis, possibilitam a neoformação óssea por suas qualidades osseocondutivas e não induzem à formação de osso ectópico...
The aim of this study was to evaluate the biological properties and biocompatibility of bovine non-demineralized lyophilized and composite bones implanted in tibiae bone cavities and at the subcutaneous level. Twenty-four rats were used and sacrificed 15 and 45 days later. At the subcutaneous level, after 15 days an inflammatory reaction was seen around biomaterial particles with the presence of giant cells and at 45 days fibrous connective tissue had also developed. No signs of ectopic bone formation were observed at tibiae regions; more bone neoformation was observed at the control group (15 days) with 42.8% of the outer cortex layer against 22.6% at Orthogen and 25% at GenMix groups. At 45 days, correspondent values for bone neoformation were 62.5% at control, 26% at Orthogen, and 35% at GenMix groups, respectively. It can be concluded that both materials tested were biocompatible aiming to bone neoformation by their osteoconductive properties with no ectopic formation sites observed...
Asunto(s)
Animales , Ratas , Huesos , Ensayo de Materiales , MúsculosRESUMEN
La piel es un tejido complejo vulnerable a procesos que alteran su estructura, integridad y funcionalidad como, por ejemplo, quemaduras, heridas crónicas y diversas enfermedades congénitas. Los avances tecnológicos en la fabricación de biomateriales y en el cultivo de células han permitido la producción de sustitutos cutáneos que han sido una alternativa terapéutica para algunas de estas complicaciones. Esta revisión pretende actualizar los aspectos generales, composición, perspectivas futuras y de aplicación de los principales sustitutos cutáneos que se ofrecen actualmente en el mercado internacional. Igualmente, presentará algunas experiencias del Grupo de Ingeniería de Tejidos y Terapias Celulares (GITTC) de la Facultad de Medicina de la Universidad de Antioquia.
The skin is a complex tissue vulnerable to different processes that may alter its structure, integrity and functionality, among them: burns, chronic wounds and various congenital diseases. Technological advances in biomaterials manufacture and cell culture have allowed the production of skin substitutes thus providing an alternative therapy for some of these complications. This review aims to update the general aspects, composition, future prospects and implementation of the most common skin substitutes currently available in the international market. Some experiences of the Tissue Engineering and Cellular Therapy Group (GITTC), at the University of Antioquia, Faculty of Medicine, in Medellín, Colombia, are also presented.